# Draft California 2012 Integrated Report( 303(d) List/305(b) Report)

# Supporting Information

## Regional Board 6 - Lahontan Region

Water Body Name: | Hilton Creek
Water Body ID: | CAR6031008020070824170247
Water Body Type: | River & Stream

DECISION ID | 30332 | Region 6
Hilton Creek

Pollutant: | Oxygen, Dissolved
Final Listing Decision: | Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Sources: | Source Unknown
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for removal from the section 303(d) list under section 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. Ten of the samples 21 exceed the water quality objective which specifies a one-day minimumus of 8.0 mg/L. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. Ten of 21 samples exceeded the 1-day minimum water quality objective and exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. History of 2010 Listing Cycle decision: Lahontan Regional Board staff had decided not to list this water body during the 2010 Listing Cycle because staff thought it had insufficient information to make a decision to list. Regional Board staff found that although these exceedances could require listing under the Listing Policy's binomial model, listing is not recommended because quarterly samples do not capture the diel, seasonal and annual variation expected in dissolved oxygen concentrations. State Board Review and Conclusion: The April 19, 2010 State Water Board staff report for the 2010 Integrated Report recommended to place this water body on the 303(d) list for dissolved oxygen based on the State Water Board staff determination that the data were collected over a broad period of time to meet section 6.1.5.3 of the Listing Policy. However, State Board staff finds there are 15 samples with six exceedences to make a decision and this meets the sample size requirements of Table 3.2 of the Listing Policy. State Water Board staff re-evaluated the available data and the recommendation has been revised. On August 4, 2010 the State Water Board approved the staff recommendation to place this water body-pollutant combination on the 303(d) list. The final language for the recommendation is: Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. Six of 15 samples exceeded the 1-day minimum water quality objective and exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

Line of Evidence (LOE) for Decision ID 30332, Oxygen, Dissolved | Region 6
Hilton Creek
LOE ID: | 32332
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The single sample collected exceeded the water quality objective.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The objective from Lahontan Basin Plan Table 3-6 for water bodies with the COLD and SPWN beneficial uses shall not be less than a one-day minimum dissolved oxygen concentration of 8.0 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Sample was collected at station 603PS0008-Hilton Creek.
Temporal Representation: | Sample collected on 7/30/2008.
Environmental Conditions: |
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan
Line of Evidence (LOE) for Decision ID 30332, Oxygen, Dissolved | Region 6
Hilton Creek
LOE ID: | 33109
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 3
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Three of 5 samples exceeded the water quality objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The objective from Lahontan Basin Plan Table 3-6 for water bodies with the COLD and SPWN beneficial uses shall not be less than a one-day minimum dissolved oxygen concentration of 8.0 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Sample was collected at station 603HIL001 (Hilton Cr, at Lake Crowley).
Temporal Representation: | Samples collected monthly August 2007 - December 2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 30332, Oxygen, Dissolved | Region 6
Hilton Creek
LOE ID: | 5819
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 15
Number of Exceedances: | 6
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Hilton Creek between 2001 and 2005 under the Region 6 SWAMP program. Dissolved oxygen concentrations ranged from 6.5 to 11.8 mg/L. Six of fifteen quarterly samples were below the 1-day minimum limit.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The water quality objective for or waters designated for the COLD and SPWN beneficial uses is a 1-day minimum of 8 mg/L (Lahontan Basin Plan Table 3-6).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Crowley Lake, was sampled.
Temporal Representation: | Fifteen measurements of dissolved oxygen were collected between August 2001 and July 2006.
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 20928 | Region 6
Hilton Creek

Pollutant: | Chloride
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. None of the samples or annual average datapoints exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. None of 16 individual samples or 5 annual average datapoints exceeded the applicable water quality objectives and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 20928, Chloride | Region 6
Hilton Creek
LOE ID: | 32263
Pollutant: | Chloride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The single sample collected did not exceed the water quality objective.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | From the Lahontan Basin Plan Table 3-17, the water quality objective for chloride in this water body is an annual average of 0.8 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Sample was collected at station 603PS0008 in Hilton Creek.
Temporal Representation: | The sample was collected on 7/30/2008.
Environmental Conditions: |
QAPP Information: | SWAMP 2008 QAPP
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan
Line of Evidence (LOE) for Decision ID 20928, Chloride | Region 6
Hilton Creek
LOE ID: | 5671
Pollutant: | Chloride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 15
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Hilton Creek between 2001 and 2005 under the Region 6 SWAMP program. Of 15 chloride samples, 10 were estimates or below the detection level. Chloride concentrations in the remaining 5 samples ranged from 0.2 to 0.75 mg/L. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
| 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for chloride is 250 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Lake Crowley, was sampled.
Temporal Representation: | Fifteen quarterly samples were collected between 2001 and 2005.
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 20928, Chloride | Region 6
Hilton Creek
LOE ID: | 5659
Pollutant: | Chloride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Hilton Creek between 2001 and 2005 under the Region 6 SWAMP program. Of 15 chloride samples, 10 were estimates or below the detection level. Chloride concentrations in the remaining 5 samples ranged from 0.2 to 0.75 mg/L.. The site-specific objective was not exceeded.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective (from Lahontan Basin Plan Table 3-17) includes an annual average of 0.8 mg/L and a 90th percentile value of 2.0 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Lake Crowley, was sampled.
Temporal Representation: | Fifteen quarterly samples were collected between 2001 and 2005. Sampling frequency was inadequate for calculation of representative annual averages.
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21160 | Region 6
Hilton Creek

Pollutant: | Dissolved oxygen saturation
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Five of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3.Five of nine samples exceeded the objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 21160, Dissolved oxygen saturation | Region 6
Hilton Creek
LOE ID: | 6082
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 4
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | OThe U.S. Geological Survey sampled Hilton Creek under the Region 6 SWAMP program. Percent saturation of dissolved oxygen in four samples collected between October 2004 and July 2005 ranged from 94 to 108 percent. The objective was not exceeded.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's regionwide narrative objective for dissolved oxygen provides that percent saturation shall not be depressed more than 10 percent nor shall the minimum dissolved oxygen concentration be less than 80 percent of saturation.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Crowley Lake, was sampled.
Temporal Representation: | Four quarterly measurements of dissolved oxygen saturation were taken between October 2004 and July 2005..
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 21160, Dissolved oxygen saturation | Region 6
Hilton Creek
LOE ID: | 44402
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 5
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Hilton Creek to determine beneficial use support and results are as follows: 5 of 5 samples exceed the criterion for Oxygen, Saturation.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Water Quality Control Plan for the Lahontan Region's water quality objective states that the dissolved oxygen concentration shall not be less than 80 percent of saturation.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Hilton Creek was collected at 1 monitoring site [ Hilton Cr, at Lake Crowley]
Temporal Representation: | Data was collected over the time period 8/16/2007-12/13/2007.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 28264 | Region 6
Hilton Creek

Pollutant: | Fecal Coliform
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status. LOE 5704 was disassociated from this decision because a duplicate LOE (5705) exists for the appropriate beneficial use/water quality objective combination: Water Contact Recreation Beneficial Use. It is not appropriate to use the MUN use to evaluate compliance with the objective that is established for the protection of Water Contact Recreation. Three lines of evidence are available in the administrative record to assess this pollutant. One of the samples exceed the water quality objective. 2012 LOE ID 34840 was not used in the final use rating because only one sample was collected per month and as such the 40 cfu/100 ml objective is more applicable. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. One of 13 samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 28264, Fecal Coliform | Region 6
Hilton Creek
LOE ID: | 34840
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 4
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Zero of the four samples exceeded the fecal coliform objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml. Water Quality Control Plan for the Lahontan Region
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The samples were collected from station 603HIL001-Hilton Cr, at Lake Crowley.
Temporal Representation: | The samples were collected once a month from September to December 2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 28264, Fecal Coliform | Region 6
Hilton Creek
LOE ID: | 5705
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 5
Number of Exceedances: | 1
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Hilton Creek under the Region 6 SWAMP program. Four of 5 fecal coliform samples collected between July 2004 and July 2005 were estimates or below the detection level. The remaining sample was 100 colonies per 100 milliliters, exceeding the limits in the water quality objective.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's objective for coliform bacteria states: "Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock wastes. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. The log mean shall ideally be based on a minimum of not less than five samples collected as evenly spaced as practicable during any 30-day period. However, a log mean concentration exceeding 20/100 ml for any 30-day period shall indicate violation of this objective even if fewer than five samples were collected." .
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Lake Crowley, was sampled.
Temporal Representation: | Five samples were collected at quarterly intervals between July 2004 and July 2005
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28264, Fecal Coliform | Region 6
Hilton Creek
LOE ID: | 32249
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 4
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Zero of the four samples exceeded the Fecal Coliform objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The fecal coliform concentration shall not exceed more than 40/100 ml.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The samples were collected from station 603HIL001 - Hilton Cr, at Lake Crowley.
Temporal Representation: | The samples were collected once a month from September to December 2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 22863 | Region 6
Hilton Creek

Pollutant: | Nitrate
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollution
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of six samples exceeded the site specific objective for COLD and Zero of 16 exceeded the objective (MCL) for MUN this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: |

Line of Evidence (LOE) for Decision ID 22863, Nitrate | Region 6
Hilton Creek
LOE ID: | 21409
Pollutant: | Nitrate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 16
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Hilton Creek between 2001 and 2005 under the Region 6 SWAMP program. Sixteen samples each were collected for nitrite and nitrite plus nitrate. Eight of 16 calculated nitrate concentrations were below the detection level. The remainder ranged from 0 to 0.53 mg/L. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
| 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for nitrate (expressed "as nitrate") is 45 mg/L, equivalent to 10 mg/L expressed "as N."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Lake Crowley, was sampled.
Temporal Representation: | Sixteen quarterly samples each were collected for nitrite and for nitrite plus nitrate between 2001 and 2005..
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22863, Nitrate | Region 6
Hilton Creek
LOE ID: | 21407
Pollutant: | Nitrate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Hilton Creek under the Region 6 SWAMP program between 2001 and 2005. Sixteen quarterly samples each were collected for nitrite and for nitrite plus nitrate. Because of estimated and below detection level values in the constituents, numerical annual average concentrations of nitrate could not be calculated for 2001, 2002, and 2003. The annual average concentrations for 2004 and 2005 were 0.059 and 0.126 mg/L. The objective was not violated.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective (from Lahontan Basin Plan Table 3-17) includes an annual average nitrate (as nitrate) concentration of 0.3 mg/L and a 90th percentile value of 0.5 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Crowley Lake, was sampled.
Temporal Representation: | Sixteen quarterly samples each were collected for nitrite and for nitrite plus nitrate between 2001 and 2005..
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22863, Nitrate | Region 6
Hilton Creek
LOE ID: | 32287
Pollutant: | Nitrate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The annual average did not exceeded the water quality objective for nitrate as nitrogen. Nitrate as N was calculated by subtracting nitrite as N data from nitrate + nitrite as N data when collected on the same day. One pair was calculated before comparing with the annual objective.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | Table 3-17 of the Basin Plan states that the water quality objective for nitrate as nitrogen for Hilton Creek is an annual average objective of 0.3 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The sample was collected at site 603PS0008 Hilton Creek.
Temporal Representation: | The sample was collected on 7/30/2008.
Environmental Conditions: |
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 22502 | Region 6
Hilton Creek

Pollutant: | Nitrate/Nitrite (Nitrite + Nitrate as N)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two line of evidence is available in the administrative record to assess this pollutant. None of the samples exceeds the California Maximum Contaminant Level (MCL). Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. None of 17 samples exceeded the MCL and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 22502, Nitrate/Nitrite (Nitrite + Nitrate as N) | Region 6
Hilton Creek
LOE ID: | 21404
Pollutant: | Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 16
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Hilton Creek between 2001 and 2005 under the Region 6 SWAMP program. Concentrations of nitrite plus nitrate in 5 of 16 samples were below the detection level. Another two samples were estimated values. Concentrations in the remaining samples ranged from 0.001 to 0.054 mg/L. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for nitrite plus nitrate is 10 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Lake Crowley, was sampled.
Temporal Representation: | Sixteen quarterly samples were collected between 2001 and 2005.
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22502, Nitrate/Nitrite (Nitrite + Nitrate as N) | Region 6
Hilton Creek
LOE ID: | 44340
Pollutant: | Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Hilton Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Nitrate/Nitrite as N.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Maximum Contaminant Level for nitrate + nitrite (as N) that is incorporated by reference in the Water Quality Control Plan, Lahontan Region is 10.0 mg/L (Water Quality Control Plan, Lahontan Region).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Hilton Creek was collected at 1 monitoring site [ Hilton Creek]
Temporal Representation: | Data was collected on a single day 7/30/2008.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 22876 | Region 6
Hilton Creek

Pollutant: | Nitrite
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollution
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of 17 samples exceeded the objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 22876, Nitrite | Region 6
Hilton Creek
LOE ID: | 21403
Pollutant: | Nitrite
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 16
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Hilton Creek between 2001 and 2005 under the Region 6 SWAMP program. Concentrations of nitrite in 8 of 16 samples were below the detection level. Concentrations in the remaining samples ranged from 0.001 to 0.002 mg/L. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for nitrite is 1 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Lake Crowley, was sampled.
Temporal Representation: | Sixteen quarterly samples were collected between 2001 and 2005.
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22876, Nitrite | Region 6
Hilton Creek
LOE ID: | 44361
Pollutant: | Nitrite
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Hilton Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Nitrite as N.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Water Quality Control Plan, Lahontan Basin, Objective for Municipal and Domestic Supply uses of inland surface waters states the following: waters shall not contain concentrations of inorganic chemicals in excess of the limits specified in California Code of Regulations, Title 22, Table 64431-A of section 64431 (Inorganic Chemicals). The maximum contaminant level listed in Table 64431-A for Nitrite as N is 1.0 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Hilton Creek was collected at 1 monitoring site [ Hilton Creek]
Temporal Representation: | Data was collected on a single day 7/30/2008.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 32058 | Region 6
Hilton Creek

Pollutant: | Nitrogen, ammonia (Total Ammonia)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the sample exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 16 samples is needed for application of table 3.. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32058, Nitrogen, ammonia (Total Ammonia) | Region 6
Hilton Creek
LOE ID: | 32481
Pollutant: | Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The single sample did not exceeded the water quality objective for unionized ammonia. Data were reported as as total ammonia as nitrogen and were converted to unionized ammonia before being compared with the objective.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan objective for unionized ammonia is a function of pH, temperature, and the presence of salmonids. The 4-day chronic criteria for unionized ammonia with salmonids present is 0.042 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The sample was collected at site 603PS0008.
Temporal Representation: | The sample was collected on 7/30/2008.
Environmental Conditions: |
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 32059 | Region 6
Hilton Creek

Pollutant: | Orthophosphate
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the sample, which used one sample to calculate and annual average, exceeds the site specific water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. One sample is not sufficient to calculate an annual average nor does a single sample capture the seasonal and annual fluctuation is streamflow or constituent level in the waterbody. 3. The single sample did not exceed the objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 16 samples is needed for application of table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32059, Orthophosphate | Region 6
Hilton Creek
LOE ID: | 32207
Pollutant: | Orthophosphate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The single sample did not exceeded the site specific objective for orthophosphate. A single sample was used to calculate an annual average. The result was reported as Orthophosphate as P, so the result was first converted (conversion dividing by 0.3322) so it could be compared to the annual average value for Orthophosphate, which is a site specific objective of 0.03 mg/L. The single sample used to compute an annual average did not exceed the site specific objective at 0.0295 mg/L (0.03 mg/L).
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | Table 3-17 of the Basin Plan states that the water quality objective for orthophosphate for Hilton Creek is an annual average objective of 0.03 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The sample was collected at site 603PS0008.
Temporal Representation: | The sample was collected on 7/30/2008.
Environmental Conditions: |
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 20877 | Region 6
Hilton Creek

Pollutant: | Specific Conductance
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. None of 25 samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Polic and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 26 samples is needed for the application of table 3.2. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 20877, Specific Conductance | Region 6
Hilton Creek
LOE ID: | 44382
Pollutant: | Specific Conductivity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 9
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Hilton Creek to determine beneficial use support and results are as follows: 0 of 9 samples exceed the criterion for Conductivity(Us).
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Secondary MCL that is incorporated by reference in the Water Quality Control Plan, Lahontan Region for specific conductance is 900 uS/cm (Water Quality Control Plan, Lahontan Region).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Hilton Creek was collected at 1 monitoring site [ Hilton Cr, at Lake Crowley]
Temporal Representation: | Data was collected over the time period 8/16/2007-12/13/2007.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 20877, Specific Conductance | Region 6
Hilton Creek
LOE ID: | 5673
Pollutant: | Specific Conductance
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 15
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Hilton Creek between 2001 and 2005 under the Region 6 SWAMP program. Specific conductance in 15 field measurements ranged from 22 to 54 uS/cm. Two additional laboratory measurements from samples collected on the same dates as field measurements were 32 and 38 uS/cm. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for specific conductance is 900 microsiemens per centimeter (uS/cm).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, HIlton Creek at Lake Crowley, was sampled.
Temporal Representation: | Fifteen quarterly field measurements and two laboratory measurements were taken between 2001 and 2005.
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 20877, Specific Conductance | Region 6
Hilton Creek
LOE ID: | 44282
Pollutant: | Specific Conductivity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Hilton Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Conductivity(Us).
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Secondary MCL that is incorporated by reference in the Water Quality Control Plan, Lahontan Region for specific conductance is 900 uS/cm (Water Quality Control Plan, Lahontan Region).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Hilton Creek was collected at 1 monitoring site [ Hilton Creek]
Temporal Representation: | Data was collected on a single day 7/30/2008.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 32061 | Region 6
Hilton Creek

Pollutant: | Sulfates
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the sample exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample did not exceed the objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 26 samples is needed for application of table 3.2. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32061, Sulfates | Region 6
Hilton Creek
LOE ID: | 32327
Pollutant: | Sulfates
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The single sample collected did not exceed the water quality objective.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | From the Lahontan Basin Plan Table 3-17, the water quality objective for sulfate in this water body is an annual average of 3.0 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Sample was collected at station 603PS0008 in Hilton Creek.
Temporal Representation: | The sample was collected on 7/30/2008.
Environmental Conditions: |
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 21084 | Region 6
Hilton Creek

Pollutant: | Total Dissolved Solids
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. None of 16 individual samples exceed the Maximum Contaminant Level. Three of 6 annual averages (calculated based on 2 to 4 samples per year) exceeded the site-specific objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. None of 16 individual samples exceeded the Maximum Contaminant Level. Three of six annual averages exceeded the site-specific objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 21084, Total Dissolved Solids | Region 6
Hilton Creek
LOE ID: | 5676
Pollutant: | Total Dissolved Solids
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 16
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Hilton Creek between 2001 and 2005 under the Region 6 SWAMP program. TDS concentrations in 16 samples ranged from 18 to 63 mg/L. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for Total Dissolved Solids (TDS) is 500 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Lake Crowley, was sampled.
Temporal Representation: | Sixteen quarterly samples were collected between 2001 and 2005.
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 21084, Total Dissolved Solids | Region 6
Hilton Creek
LOE ID: | 5675
Pollutant: | Total Dissolved Solids
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 2
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Hilton Creek between 2001 and 2005 under the Region 6 SWAMP program. TDS concentrations in 16 samples ranged from 18 to 63 mg/L. Annual average concentrations ranged from 20 to 37 mg/L. The annual average objective was exceeded in 2 of 5 years.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-pecific objective for Total Dissolved Solids (TDS) in Lahontan Basin Plan Table 3-17, includes an annual average of 28 mg/L and a 90th percentile value of 34 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Lake Crowley, was sampled.
Temporal Representation: | Sixteen quarterly samples were collected between 2001 and 2005.
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 21084, Total Dissolved Solids | Region 6
Hilton Creek
LOE ID: | 32223
Pollutant: | Total Dissolved Solids
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The annual average for TDS for this data set was 33.68 which exceeds the Water Quality Objective. LOE ID 34507 written for Salinity/Chlorides/TDS for Hilton Creek based on the same dataset was retired.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-pecific objective for Total Dissolved Solids (TDS) in Lahontan Basin Plan Table 3-17, includes an annual average of 28 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data were collected at the following station: 603HIL001-Hilton Creek at Crowley Lake.
Temporal Representation: | Samples were collected on 8/16/2007, 9/27/2007, 10/11/2007, 11/12/2007, 12/13/2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 22890 | Region 6
Hilton Creek

Pollutant: | Total Nitrogen as N
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the six annual average datapoints exceeded the site-specific objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 22890, Total Nitrogen as N | Region 6
Hilton Creek
LOE ID: | 32288
Pollutant: | Total Nitrogen as N
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The annual average did not exceeded the water quality objective for total nitrogen. Total nitrogen was calculated by summing nitrate + nitrite as N data with TKN data when they were collected on the same day. One pair was summed before comparing with the annual objective.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | Table 3-17 of the Basin Plan states that the water quality objective for total nitrogen for Hilton Creek is an annual average objective of 0.5 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The sample was collected at site 603PS0008 Hilton Creek.
Temporal Representation: | The sample was collected on 7/30/2008.
Environmental Conditions: |
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan
Line of Evidence (LOE) for Decision ID 22890, Total Nitrogen as N | Region 6
Hilton Creek
LOE ID: | 21406
Pollutant: | Total Nitrogen as N
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Hilton Creek under the Region 6 SWAMP program between 2001 and 2005. Sixteen quarterly samples each were collected for total Kjeldahl nitrogen and nitrite plus nitrate. Because of estimated and below detection level values in the constituents, the annual average concentrations of total nitrogen for 2001, 2002, and 2003 were estimates. The annual average concentrations for 2004 and 2005 were 0.207 and 0.160 mg/L. The objective was not violated.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective (from Lahontan Basin Plan Table 3-17) includes an annual average total nitrogen concentration of 0.5 mg/L and a 90th percentile value of 0.6 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Crowley Lake, was sampled.
Temporal Representation: | Sixteen quarterly samples each were collected for total Kjeldahl nitrogen and nitrite plus nitrate between 2001 and 2005..
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 22931 | Region 6
Hilton Creek

Pollutant: | pH
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | The Lahontan Basin Plan's narrative pH objective is an antidegradation-based objective that requires that there be no change greater than 0.5 pH units in waters designated for the Cold Freshwater Habitat (COLD) or Warm Freshwater Habitat beneficial uses. Listing Policy Section 3.10 contains directions for assessment based on trends in water quality. These directions include requirements to establish specific baseline conditions and specify the influence of seasonal and interannual effects. Three lines of evidence available to support this decision. There are not enough pH samples to establish baseline conditions (including diel, seasonal, annual and interannual variations) or to detect changes in the pH regime due to controllable factors, if such trends exist.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because the data are insufficient to document baseline and trend conditions as required by section 3.10 of the listing policy.

Line of Evidence (LOE) for Decision ID 22931, pH | Region 6
Hilton Creek
LOE ID: | 5672
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 14
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Hilton Creek between 2001 and 2005 under the Region 6 SWAMP program. The pH values in 14 field measurements ranged from 7.1 to 7.9 units.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's regionwide objective for pH states: " In fresh waters with designated beneficial uses of COLD or WARM, changes in normal ambient pH levels shall not exceed 0.5 pH units. For all other waters of the region, the pH shall not be depressed below 6.5 nor raised above 8.5 units. The Regional Board recognizes that some waters of the Region may have natural pH levels outside of the 6.5 to 8.5 range. Compliance with the pH objective for these waters will be determined on a case-by-case basis."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Lake Crowley, was sampled.
Temporal Representation: | Fourteen quarterly pH measurements were collected between 2001 and 2005.
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22931, pH | Region 6
Hilton Creek
LOE ID: | 33110
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 0
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | There were 5 samples with pH ranging from 7.0 to 8.2. The normal ambient pH level for this water body is unknown and so it is unknown whether any exceedences occured.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The applicable objective states: "In fresh waters with designated beneficial uses of COLD or WARM, changes in normal ambient pH levels shall not exceed 0.5 pH units." (Lahontan Basin Plan).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data were collected at the following station: 603HIL001 (Hilton Cr, at Lake Crowley).
Temporal Representation: | Samples were collected between August and December 2007
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 22931, pH | Region 6
Hilton Creek
LOE ID: | 33117
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 0
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | There was 1 sample with a pH 8.66. The normal ambient pH level for this water body is unknown and so it is unknown whether any exceedences occured.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The applicable objective states: "In fresh waters with designated beneficial uses of COLD or WARM, changes in normal ambient pH levels shall not exceed 0.5 pH units." (Lahontan Basin Plan).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data were collected at the following station: 603PS0008 (Hilton Creek).
Temporal Representation: | Sample was collected on 7/30/2008.
Environmental Conditions: |
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan

DECISION ID | 22877 | Region 6
Hilton Creek

Pollutant: | Phosphate
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the annual average datapoints exceeds the site-specific water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. None of 4 annual average datapoints exceeded the site-specific objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 22877, Phosphate | Region 6
Hilton Creek
LOE ID: | 21408
Pollutant: | Phosphate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 4
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Hilton Creek under the Region 6 SWAMP program between 2002 and 2005. Six of fourteen samples for PO4 as P were below the detection level. Concentrations in the remaining samples ranged from 0.001 to 0.017 mg/L. Fourteen calculated concentrations of P04 included 6 below detection level values; the remainder ranged from 0.003 to 0.052 mg/L. of . Because of the below detection level values, the annual average concentrations for 2002 and 2003 could not be calculated. The annual average concentrations for 2004 and 2005 were 0.015 and 0.001 mg/L. The objective was not violated. An additional sample for hydrolyzable P plus PO4 was collected on November 27, 2001. The concentration was 0.08 mg/L.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective (from Lahontan Basin Plan Table 3-17) includes an annual average dissolved orthophosphate concentration of 0.03 mg/L and a 90th percentile value of 0.05 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Crowley Lake, was sampled.
Temporal Representation: | Fourteen quarterly samples for PO4 as P were collected between 2002 and 2005. One sample for hydrolyzable P plus PO4 was collected on November 27, 2001.
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 22948 | Region 6
Hilton Creek

Pollutant: | Phosphorus
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. No biological data are available for assessment whether any of the chemical samples exceeds the water quality objective for biostimulatory substances. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used do not satisfy the data quality requirements of section 6.1.4 of the Policy due to an error in the SWAMP QAPP regarding holding times for total phosphorus samples. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. No biological data are available for assessment of compliance with the objective for biostimulatory substances and the 12 total phosphorus samples cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle. After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because there is a quality assurance problem with the chemical data and no biological data are available for assessment of compliance with the applicable water quality objective.

Line of Evidence (LOE) for Decision ID 22948, Phosphorus | Region 6
Hilton Creek
LOE ID: | 21412
Pollutant: | Phosphorus
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Hilton Creek under the Region 6 SWAMP program between 2002 and 2005. Concentrations of total phosphorus in 12 quarterly samples ranged from 0.004 to 0.034 mg/L.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan does not include a site-specific objective (SSO) for total phosphorus in Hilton Creek. The narrative objective for biostimulatory substances states: "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Crowley Lake, was sampled.
Temporal Representation: | Twelve quarterly samples were collected between 2002 and 2005..
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | Sampling and analysis were done according to the SWAMP QAPP. However, in July 2009 an error was discovered in the QAPP related to holding times for total phosphorus samples that affects the validity of data for the Lahontan Region The holding time for samples that are not acid-preserved.should be 48 hours rather than 28 days as indicated in the QAPP. "Low level" phosphorus analyses, without acid preservation, are used in the Lahontan Region's SWAMP program. .
QAPP Information Reference(s):

DECISION ID | 21739 | Region 6
Hilton Creek

Pollutant: | Sediment
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: The Lahontan Basin Plan's narrative water quality objective is an antidegradation based objective that provides that there shall be no increases in suspended sediment concentrations or loads. This pollutant is being considered for placement on the section 303(d) list under section 3.10 of the Listing Policy, which deals with trends in water quality. One line of evidence, based on quarterly sampling, is available in the administrative record to assess this pollutant. It includes 16 suspended sediment concentration values and 8 suspended sediment load values calculated from instantaneous discharge measurements. Suspended sediment concentrations and loads are dependent on flows and can change rapidly over a short time during storm or snowmelt runoff events. Quarterly samples are insufficient to capture these short term events and therefore are insufficient to define natural background suspended sediment concentrations and loads, or to detect trends. Listing Policy Section 3.10 requires that natural background conditions be established. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. Sampling frequency was insufficient to establish natural background conditions and therefore does not meet the requirements of Listing Policy Section 3.10. 3. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21739, Sediment | Region 6
Hilton Creek
LOE ID: | 5674
Pollutant: | Sediment
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 16
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Hilton Creek between 2001 and 2005 under the Region 6 SWAMP program. Suspended sediment concentrations in 16 samples ranged from 18 to 63 mg/L. Instantaneous discharges measured concurrenty ranged from 1.2 to 33 cubic feet per second. Calculated suspended sediment loads (for 8 samples) ranged from 0.01 to 0.89 tons per day.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The objective from the Lahontan Basin Plan states: "The suspended sediment load and suspended sediment discharge rate of surface waters shall not be altered in such a manner as to cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Lake Crowley, was sampled.
Temporal Representation: | Sixteen quarterly suspended sediment samples were collected between 2001 and 2005. Eight suspended sediment load calculations were done for suspended sediment and flow data collected between 2003 and 2005.
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21265 | Region 6
Hilton Creek

Pollutant: | Temperature, water
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: The Lahontan Basin Plan's narrative temperature objective is an antidegradation-based objective that requires that there be no change in temperature in waters designated for the Cold Freshwater Habitat (COLD) beneficial use. The objective does not include specific numerical limits for protection of the COLD use. Listing Policy Section 3.10 contains directions for assessment based on trends in water quality. These directions include requirements to establish specific baseline conditions and specify the influence of seasonal and interannual effects. Three line of evidence is available to support this decision. There are not enough temperature samples to establish baseline conditions (including diel, seasonal, annual and interannual variations in temperature) or to detect declining trends in the temperature regime if such trends exist. Because temperature samples were collected only quarterly, weekly and monthly average data are not available for comparison with guidelines in the scientific literature for the temperature requirements of sensitive aquatic species such as salmonids, as directed in Listing Policy Section 6.1.5.9.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 21265, Temperature, water | Region 6
Hilton Creek
LOE ID: | 44318
Pollutant: | Temperature, water
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Hilton Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Water Temperature.
Data Reference: | Statewide Perennial Streams Assessment 2008
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Water Quality Control Plan for the Lahontan Region's water quality objective for all surface waters states the following: The natural receiving water temperature of all waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such an alteration in temperature does not adversely affect the water for beneficial uses. For waters designated COLD, the temperature shall not be altered.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: | Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference: | Fish introductions in CA: History and impact on native fishes. Davis, CA: University of CA, Davis
Spatial Representation: | Data for this line of evidence for Hilton Creek was collected at 1 monitoring site [ Hilton Creek]
Temporal Representation: | Data was collected on a single day 7/30/2008.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): | Surface Water Ambient Monitoring Program Quality Assurance Program Plan
Line of Evidence (LOE) for Decision ID 21265, Temperature, water | Region 6
Hilton Creek
LOE ID: | 5677
Pollutant: | Temperature, water
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 16
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Hilton Creek between 2001 and 2005 under the Region 6 SWAMP program. Temperatures in 16 quarterly measurements taken ranged from 0 to 21 degrees Celsius.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The applicable language from the Lahontan Basin Plan's objective for temperature states: "The natural receiving water temperature of all waters shall not be altered unless it can be demonstrated to the satisfaction fo the Regional Board that such an alteration in temperature does not adversely affect the water for beneficial uses. For waters designated WARM, water temperature shall not be altered by more than five degrees Fahrenheit ... above or below the natural temperature. For waters designated COLD, the temperature shall not be altered. Temperature objectives for COLD interstate waters and WARM interstate waters are as specified in the Water Quality Control Plan for Control of Temperature in The Coastal and Interstate Waters and Encosed Bays and Estuaries of California including any revisions."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Lake Crowly, was sampled.
Temporal Representation: | Sixteen quarterly measurements of water temperature were taken between 2001 and 2005.
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 21265, Temperature, water | Region 6
Hilton Creek
LOE ID: | 44263
Pollutant: | Temperature, water
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Hilton Creek to determine beneficial use support and results are as follows: 0 of 5 samples exceed the criterion for Water Temperature.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Water Quality Control Plan for the Lahontan Region's water quality objective for all surface waters states the following: The natural receiving water temperature of all waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such an alteration in temperature does not adversely affect the water for beneficial uses. For waters designated COLD, the temperature shall not be altered.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: | Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference: | Fish introductions in CA: History and impact on native fishes. Davis, CA: University of CA, Davis
Spatial Representation: | Data for this line of evidence for Hilton Creek was collected at 1 monitoring site [ Hilton Cr, at Lake Crowley]
Temporal Representation: | Data was collected over the time period 8/16/2007-12/13/2007.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 22962 | Region 6
Hilton Creek

Pollutant: | Total Kjeldahl Nitrogen (TKN)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. No biological data are available for assessment whether of the chemical samples exceeds the water quality objective for biostimulatory substances. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. No biological data are available for assessment of compliance with the objective for biostimulatory substances. The chemical data cannot be assessed using Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because no biological data are available for assessment of compliance with the applicable water quality objective.

Line of Evidence (LOE) for Decision ID 22962, Total Kjeldahl Nitrogen (TKN) | Region 6
Hilton Creek
LOE ID: | 21405
Pollutant: | Total Kjeldahl Nitrogen (TKN)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 16
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Hilton Creek under the Region 6 SWAMP program between 2001 and 2005. One of 16 quarterly samples for TKN was an estimated value. Concentrations of TKN in the other samples ranged from 0.03 to 0.32 mg/L.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan does not include a site-specific objective (SSO) for total Kjeldahl nitrogen (TKN) in Hilton Creek. The narrative objective for biostimulatory substances states: "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Crowley Lake, was sampled.
Temporal Representation: | Sixteen quarterly samples were collected between 2001 and 2005..
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 22947 | Region 6
Hilton Creek

Pollutant: | Turbidity
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. Separate lines of evidence were prepared for data expressed as NTU and NTRU. The two types of units are measured differently and are not directly comparable. There are no specific state or federal standards or criteria for turbidity expressed as NTRU. None of the samples expressed as NTU exceeds the Maximum Contaminant level. The Lahontan Basin Plan's narrative turbidity objective is a non-degradation objective, and sample numbers are insufficient to establish baseline conditions or detect trends as required under Listing Policy Section 3.10. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and turbidity values in streams of the Lahontan Region. 3. None of 11 samples expressed as NTU exceeded the Maximum Contaminant Level and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. It is not possible to determine whether the narrative turbidity objective was exceeded because the requirements of Listing Policy Section 3.10 were not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 22947, Turbidity | Region 6
Hilton Creek
LOE ID: | 21411
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 4
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey measured turbidity as NTRU at Hilton Creek between 2004 and 2005 under the Region 6 SWAMP program. Three of four turbidity measurements reported as NTRU were below detection levels; the remaining sample was 27 NTRU.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal water quality standards or criteria for turbidity expressed as NTRU. The California Maximum Contaminant Level (MCL) for turbidity is 5 NTU.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Lake Crowley, was sampled.
Temporal Representation: | Four quarterly turbidity measurements reported as NTRU were taken in 2004 and 2005..
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22947, Turbidity | Region 6
Hilton Creek
LOE ID: | 5679
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 11
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey measured turbidity as NTU at Hilton Creek between 2001 and 2004 under the Region 6 SWAMP program. . Eleven turbidity measurements recorded as NTU ranged from <2.0 to 5 NTU. Four of these samples were estimated or below detection level values. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for turbidity is 5 NTU.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Lake Crowley, was sampled.
Temporal Representation: | Eleven quarterly turbidity measurements expressed as NTU were taken between 2001 and 2004.
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22947, Turbidity | Region 6
Hilton Creek
LOE ID: | 21410
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 4
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey measured turbidity as NTRU at Hilton Creek between 2004 and 2005 under the Region 6 SWAMP program. Three of four turbidity measurements reported as NTRU were below detection levels; the remaining sample was 27 NTRU.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The regionwide turbidity objective in the Lahontan Basin Plan states: "Waters shall be free of changes in turbidity that cause nuisance or adversely affect the water for beneficial uses. Increases in turbidity shall not exceed natural levels by more than 10 percent."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Lake Crowley, was sampled.
Temporal Representation: | Four quarterly turbidity measurements expressed as NTRU were taken in 2004 and 2005..
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22947, Turbidity | Region 6
Hilton Creek
LOE ID: | 5678
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 11
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey measured turbidity as NTU at Hilton Creek between 2001 and 2004 under the Region 6 SWAMP program. . Eleven turbidity measurements recorded as NTU ranged from <2.0 to 5 NTU. Four of these samples were estimated or below detection level values.
Data Reference: | 2007. SWAMP Data for the Owens Hydrologic Unit
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The regionwide turbidity objective in the Lahontan Basin Plan states: "Waters shall be free of changes in turbidity that cause nuisance or adversely affect the water for beneficial uses. Increases in turbidity shall not exceed natural levels by more than 10 percent."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Hilton Creek at Lake Crowley, was sampled.
Temporal Representation: | Eleven quarterly turbidity measurements expressed as NTU were collected between 2001 and 2004
Environmental Conditions: | Hilton Creek is a tributary of Crowley Lake, a reservoir on the Owens River. The creeks headwaters are near the Sierra Nevada crest. Section 319-funded watershed restoration work to address livestock grazing problems has been completed. In addition to the Cold Freshwater Habitat beneficial use, Hilton Creek is designated for the Spawning, Reproduction and Development use.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):